Fix race with table init channel

table.go

@@ -216,10 +216,6 @@ func (t *genTable[Obj]) RegisterInitializer(txn WriteTxn, name string) func(Writ
 						slices.Clone(table.pendingInitializers),
 						func(n string) bool { return n == name },
 					)
-					if !table.initialized && len(table.pendingInitializers) == 0 {
-						close(table.initWatchChan)
-						table.initialized = true
-					}
 				}
 			})
 		}

txn.go

@@ -459,9 +459,18 @@ func (txn *txn) Commit() ReadTxn {
 	root := *db.root.Load()
 	root = slices.Clone(root)
 
+	var initChansToClose []chan struct{}
+
 	// Insert the modified tables into the root tree of tables.
 	for pos, table := range txn.modifiedTables {
 		if table != nil {
+			// Check if tables become initialized. We close the channel only after
+			// we've swapped in the new root so that one cannot get a snapshot of
+			// an uninitialized table after observing the channel closing.
+			if !table.initialized && len(table.pendingInitializers) == 0 {
+				initChansToClose = append(initChansToClose, table.initWatchChan)
+				table.initialized = true
+			}
 			root[pos] = *table
 		}
 	}
@@ -480,6 +489,11 @@ func (txn *txn) Commit() ReadTxn {
 		txn.Notify()
 	}
 
+	// Notify table initializations
+	for _, ch := range initChansToClose {
+		close(ch)
+	}
+
 	txn.db.metrics.WriteTxnDuration(
 		txn.handle,
 		txn.tableNames,